The present invention relates to valves.
In particular, the present invention relates to fairly large valves having one inlet port and two outlet ports capable of controlling the flow of a fluid such as a gas through relatively large ducts. For example, the present invention may be used in connection with turbines such as gas turbines in order to control the flow of the exhaust of a gas turbine either through a steam generator or to a bypass stack.
Although installations of the above type do not necessarily operate at very large pressures, they do operate at relatively high temperatures, and considerable problems are encountered in providing valves which can be effectively operated so as to reliably close ducts through which a gas flows. Such ducts may be, for example, of a rectangular configuration having a long dimension on the order of 12 feet and a transverse dimension of between 2 and 3 feet, for example, so that a relatively large amount of flue gas may be handled in such a duct. The temperatures which are encountered in such installations may be on the order of 1000.degree. F.
With installations of the above general type considerable problems are encountered in controlling the flow of a fluid through the duct inasmuch as the closure must be maintained over a long distance and in view of the relatively high temmperatures it is difficult to provide a reliable seal with the large temperature range which is encountered. If, for example, reliance is made upon relatively soft material to achieve the required seal, such a material requires frequent replacement as well as a complex method of attachment, such as the requirement of removing and replacing a large number of bolts. Moreover, conventional valves to serve purposes as set forth above have complex power-operated mechanisms for opening and closing the valves, and these mechanisms for operating the valve between its open and closed positions involve a further disadvantage in the structure.